Its easy to kill sunbreakers with a variety of supers. Plus, supers should cancel supers in my opinion. I think a defender should simply lose the bubble when hit by 3 golden guns or a nova bomb and not cost his/her life in the process (as that would be an equal super cancellation). I think 2 shots to kill a sunbreaker is fair seeing that they can two shot a blade dancer and storm caller and still have a hammer or two spare. I have seen a storm caller wipe out two hammer of sols simultaneously before (quite a sight to see, but I was pissed to have wasted my super as a result though....he took all the kills for himself.)